Multicolor screen film



ug 23, i932. y J. E. THCRNTON 39873,@73

LULTICOLOR SCREEN` FILMy I Filed Feb. 16, 1927 2 Sheets-Sheet l Aug,23', i932. J. E. THQRNTQN MULTICOLOR scnEEN NLM Filed Feb. 16.. 1927 um@n f Patented Aug. 23, 1932 UNITED STATES' PATENu OFI-'ics-J'OHNZED'WABD THORNTON, OF WEST HAHPSTEAD, LONJON, ENGLAND, ASSIGNORVTJOHN OWDEN' OBRIEN, 0F MANCHESTER, ENGLAND MULTICOLOB SCREW FILEApplication le. February 16, 1927,

This invention relates to the manufacture of multi-color screens andfilm-supports for the production of negatives or positives of themulti-color screen-type, and is applicable to thin iexible films forroll-film, cameracartridges and film-packs, also for thick stiff flatlms, rigid glass plates, and for continuous kinematograph film.

The object of the invention' is to form the color screen in h purelyphotographic and dye processes, obviatirig the need for any printing andsubsequent washing away ofv fatty-resists or other equivalent methodsgenerall used in screen making, and then to com ine such half-screens bycrossing the lines of one upon the other to produce the required mosaicpattern, andv in forming such half-screens upon opposite sides of acentral transparent support or upon two thin supports that areeventually cemented together to make up such support;

lt has already been proposed in the production of two color screens ltoprint resist lines in printing ink, fatty or resinoussubstances, Adyethe Celluloid spaces, between, remove the resist, and dye the clearspaces left.

- Many modiications of this syst-em have been proposed, and inpractically all these methods theseveral colors 'have been applied toone side of the support, and it has been necessary to accuratelyregister one color with the other to reduce a suitable mosaic. The.necessity or such accurate registration has made all `these methods oflittle or no value for, manufacture upon a large scale.

The fact that the present system dispenses with registration entirelyobviates objection; and the vfact that the screen is made in two partsas two-half screens still further simplifies themanufacturing'processes; and the use of purely photographic printingmethods reduces suchmanufacture to processes of great precision,simplicity, regularity of results, and enables the product to be turnedout entirely by automatic machinery.

The invention consists of a single and complete multi-color screen l'and support com` prislng four or three colors manuactured f two parts ortwo halt-screens this great Serial No. 188,765, and iu Great BritainMarch 16, 1926.

,without need for any registration by crossing two half screens whichare respectively formed upon opposite sides of a transparent support orupon two transparent supports, one half screen being produced with twocolors by alternating' llnes of insoluble colored and non-insolublecolored colloid and the other half screen being produced withtwodifferent colors by alternating lines of .insoluble colored andnon-insoluble colored colloid or with lines of one color alternatingwith transparent non-colored lines, the colors be,- ing eventuallymordanted and xiixed, the correct colorings being obtained by crossingthe colors on the two half-screens.

The invention will be described with reference to the accompanyingdrawings Figs. 1 and 2 show two arrangements of tour-color 'screensbuilt up from two halfscreens.

Figs. 3 and 4 show two arrangements of three-color screens built up fromtwo halfscreens. Y

Fig. 5 shows another arrangement of fourcolor screen built up from twohalf screens in which the lines run diagonally on'each screen.

Fig. 6 is another arrangement of four-color screen built up from twohalf screens in y which the lines on one screen are diagonal and on theother screen are longitudinal or transverse.

Fig. 7 is a perspective-view of a `strip of kinematograph film-supportformed in accordance with the invention.

Fig. 8 isa section of same.

Fig. 9 is a section of a camera ilm with a non-curling gelatine layer onthe back' thereof. l

Fig. 10 is a section of a relatively thick support of non-flexible ornon-rollable type such as glass plates or very thick Celluloid.

Fig. 11 is a perspective view of a strip of kinematograph film supportformed in ac- 'y cordance with the invention in -which the two films areunited back to back and y Fig. 12 is a perspectiveview of a strip ofkinematograph film support formed in accordance with the invention inwhich the two half screens are united back to face.

- to two thinJ` films which are ultimately ce- May 22,v

-c'lucing when the two half screens are mented together to form a singlesupport as inspecification of Patent No. 1,670,671 dated 1928 one faceof each thin film is printed by exposure through a line-screen, untilthe portions of collold exposed through the clear spaces are renderedinsoluble and4 non-absorbent; the portions protected by the o aque linesof the screen remain soluble and a sorbent.

The four-color screen shownin Fig. l is built up from the twohalf-screens, one of which contains the complementary pair of colors redand blue-green, and the other con- .tains the complementary pair ofcolors, yellow and violet, the colors in each pair being exactlycomplementary to each other; prosuperlmposed and cemented together, in acrossed position, a support and screen comprising the following colors:--orange, blue-violet, green and red-violet.

The-four-color screen shown in Fig. 2 is built up from two half-screens,one of contains the complementary pair of colors,

red and green, crossed by the complementary pair of colors, blue andyellow in the other half-screens producing a finished support and screencomprising the following. colors Violet, orange, yellow-green andbluegreen.

One arrangement4 of a three-color screen, built up from the half-screensis shown in Fig. 3, one half-screen contains red and yellowclosetogether, and crossed by the other containing t e single color blueseparated by uncolored spaces; producing when the two half-screens aresu erimposed and cemented together with the lue crossing the red and 5yellow a support'and screen comprising the following colors :-'Red,green.

yellow, violet and A similar arrangement. of a three-color screen builtup from two half-screens is shown in Fig. 4, one half-screen containsred and yellow-green, crossed'by the other containing the single colorblue separated by uncolored spaces; producing a finished support andscreen comprising the following colors Red, yellow-green, violet and'blue-green.

AIn the three-color groups Figs. 3 and 4 the pair of colors are notexactly complementary, as is the case in thefour-color groups.

screen is built up from two two-color half screens, one half screencontaining the colors red and blue` and the other the colors yellowscreen is built Aup'rfrom two two-'color half screens, one half screencontaining the colors red and blue and the other the colors yellow andviolet as in Fig. 1, but the lines of color In the arrangement shown inFig. 5 the of one screen are arran ed diagonally and on the other eithervertica y or transversely.

Figs. 7 and 8 show a kinematograph film produced according to theinvention, being built up of two thin celluloid layers forming thesupport each bearing a half-screen layer, the two thin films, which areeach half-supports, being cemented together withI the screens inside.There is thus formed a single support of the exible-film type, upon ones side of which is then coated first an adhesive substratum and then asensitive layer of panchromatic elatino-silver-bromide emulsion.

There is t us produced a flexible or rollable lm of any size or widthsuch as employed for roll-,film cameras, for ilm-packs, or forkinematograph film-ribbons.

Fig.' 9 vshows a similar film one face of which is coated with anadhesive substratum and' then a sensitive layer of panchromaticgelatino-silver-bromide emulsion, and the other face with a layer ofgelatine on Ithe back of the same thickness as the layer of emulsion onthe other face, thus forming a non-curlin .film suitable fory roll-filmcameras and camera film. y

In Fig. 10 the invention is illustrated as applied to thickersupports'of the non-fiexible or non-rollable description, such as glassplates or very thick stiff celluloid films. One half the screen isformed upon such thick support, the other half being formed upon anextremely thin lsupport of celluloid y(as in Figs. 7 and 8) which Viscemented to the stiff half of the support, with the screens inward. Theface of the celluloid is next coated with an adhesive substratum andfinally with agpanchromatic emulsion as described with re .erence toFigs. 7 and 8.

Instead of thetwo half screens being united together face to face asshown in Figs. 7 and 8 theyr may be united back to back as shown in ig.11 or back to face as shown in Fig. 12.

The approximate thickness of the various layers of the lm illustrated inFigs. 7 to l2 are as'follows For the films- Each celluloid layer n10-0-inch thick.

Each screen layer inch thick.

Each cement layer ,U-0- inch thick, these three layers duplicatedforming a complete flexible support.

One substratum layeil m inch thick.

One emulsion layer/T01mr inch thick these latter being applied to one ofthe outer faces of the flexible support. i

Where a non-curling film is other face is lprovided with A substratumlayer w30-0- inch thick. y.A gelatine layer n10-G inch thick.

For thick rigid films the celluloid is inch thick and for glass platesthe glass is about if inch thick, the other layers remaining the same.

required the m packs for such as a nonroll All the above figures areapproximate and may/:be varied as required.

In all cases the colloid comprises a very thin layer of gelatine,sh-glue, albumen, or the like or a mixture thereof. The sensitizerpreferably is a solution of a bichromate salt. The colorin l matter is asuitable dye comprising one co or of the complete set of colors. T hedye and sensitizer may be mixed with the colloid before it is applied tothe support by the usual coating apparatus. Or one only may beincorporated with the colloid, the other being applied after the coatinghas been dried by passing the coated support through a bath untilsufficient of -either the dye or sensitizeras the case'may be has beenabsorbed.

After the colloid layer has been exposed and printed as aforesaid it iswell washed to remove all dye and sensitizer from the parts that werecovered by the opaque lines of the screen, and which still remainsoluble, so that there is no difficulty in removing the sensitizer andcolor. The other lines corresponding to the transparent lines of thescreen have become insoluble and the dye is therefore locked up therein,the result being a colloid layer comprising insoluble colored lines withabsorbent uncolored spaces between.

The layer is then dried in order to thoroughly harden the insolublelines, afterl which the intermediate absorbent lines of colloid are dyedwith another color. This exactly fills the spaces between the insolublecolored lines, the final result after slight rinsing in water andsubsequent drying e ing to produce a line-screen of two colors. Thesecond colored lines are finally mordanted or rendered insoluble toprevent the color washing out. l

In the case of a color screen-support containing three colors as shownin Figs. 3 and 4 the second thin film is printed by similar methods butwith the difference that only one set of lines are printed and colored,the intermediate spaces being leftuncolored.

In the case of a color screen-support containing four colors as shown inFigs.4 1 and 2 two colors areformed on the second thin-filml by dyeingthe intermediate lines as frstde.- scribed'.

Instead of sensitizing the screen-layers with a bichromate salt, iron'orother suitable.

salts may be used. Or silver sensitizing may be substituted, in whichcase the exposed layer requires developing and afterwards treating withan oxidizing bath that will render the colloid insoluble in direct ratioto the deposit of metallic silver. This brings the colloid topractically the same insoluble and soluble conditions as in thehereinbefore described' bichromate method. The final step is to dissolvethe silver by any suitable v known bath in order to leavel transparent(instead of opaque) colored lines and then to thoroughly wash the film.

What I claim as my invention and desire to protect as my invention is1`. A multl-color screen and support comprising a transparent support aplurality of lines in insoluble colored colloid printed upon one side ofsaid support, a plurality of differently colored dyed lines alternatingwith `the printed lines on said support, a second transparent support, aplurality of lines in insoluble colored colloid printed upon oneti-color screen upon two transparent supy ports which consists incoating each support with differently colored colloid photographicallyprinting a plurality of insoluble lines upon the colloid washing awaythe unprinted soluble colloid, dyeing the spaces between the printedlines in different colors differing from the printed lines andassembling the two half screens with the lines on one crossing the lineson the other. f

3. A multi-color .screen and lsupport formed from two photographicallyproducedv multicolor pattern half-screens crossed to avoid registration,an adhesive substratum coated upon one side of the support and. a layerof sensitive panchromatic elatino-silver-halid emulsion superimpose uponthe substratum.

4. A multi-color screen and support formed from two photographicallyproduced multi-color pattern half-screens crossed to avoid registration,an adhesive substratum coated upon one side ofthe support, a layer ofsensitive panchromatic gelatine-silverhalid emulsion superimposed uponthe substratum, a secondadhesive substratum coated upon the other sideof the support and a layer of non-sensitive plain gelatine upon thesecond substratum.

In testimony whereof I have hereunto set my hand.

JOHN EDWARD THORNTON.

